我想检查一下我是否可以在iOS上使用Cocoa Touch库或在macOS上使用Cocoa库连接互联网。

我想出了一个方法来做这个使用NSURL。我的方法似乎有点不可靠(因为即使谷歌也可能有一天宕机,依赖第三方似乎很糟糕),虽然如果谷歌没有响应,我可以检查其他一些网站的响应,但这似乎是浪费和不必要的应用程序开销。

- (BOOL)connectedToInternet {
    NSString *URLString = [NSString stringWithContentsOfURL:[NSURL URLWithString:@"http://www.google.com"]];
    return ( URLString != NULL ) ? YES : NO;
}

是我做得不好,(更不用说stringWithContentsOfURL已弃用在iOS 3.0和macOS 10.4),如果是这样,有什么更好的方法来实现这一点?


当前回答

//
//  Connectivity.swift
// 
//
//  Created by Kausik Jati on 17/07/20.
// 
//

import Foundation
import Network

enum ConnectionState: String {
    case notConnected = "Internet connection not avalable"
    case connected = "Internet connection avalable"
    case slowConnection = "Internet connection poor"
}
protocol ConnectivityDelegate: class {
    func checkInternetConnection(_ state: ConnectionState, isLowDataMode: Bool)
}
class Connectivity: NSObject {
    private let monitor = NWPathMonitor()
    weak var delegate: ConnectivityDelegate? = nil
    private let queue = DispatchQueue.global(qos: .background)
    private var isLowDataMode = false
    static let instance = Connectivity()
private override init() {
    super.init()
    monitor.start(queue: queue)
    startMonitorNetwork()
}
private func startMonitorNetwork() {
    monitor.pathUpdateHandler = { path in
        if #available(iOS 13.0, *) {
            self.isLowDataMode = path.isConstrained
        } else {
            // Fallback on earlier versions
            self.isLowDataMode = false
        }
        
        if path.status == .requiresConnection {
            print("requiresConnection")
                self.delegate?.checkInternetConnection(.slowConnection, isLowDataMode: self.isLowDataMode)
        } else if path.status == .satisfied {
            print("satisfied")
                 self.delegate?.checkInternetConnection(.connected, isLowDataMode: self.isLowDataMode)
        } else if path.status == .unsatisfied {
            print("unsatisfied")
                self.delegate?.checkInternetConnection(.notConnected, isLowDataMode: self.isLowDataMode)
            }
        }
    
    }
    func stopMonitorNetwork() {
        monitor.cancel()
    }
}

其他回答

Reachability类可以确定一个设备的互联网连接是否可用…

但在访问内网资源时:

使用可达性类ping内网服务器总是返回true。

因此,在这种情况下,一个快速的解决方案是创建一个名为pingme的web方法以及服务上的其他web方法。 pingme应该返回一些东西。

所以我写了下面关于普通函数的方法

-(BOOL)PingServiceServer
{
    NSURL *url=[NSURL URLWithString:@"http://www.serveraddress/service.asmx/Ping"];

    NSMutableURLRequest *urlReq=[NSMutableURLRequest requestWithURL:url];

    [urlReq setTimeoutInterval:10];

    NSURLResponse *response;

    NSError *error = nil;

    NSData *receivedData = [NSURLConnection sendSynchronousRequest:urlReq
                                                 returningResponse:&response
                                                             error:&error];
    NSLog(@"receivedData:%@",receivedData);

    if (receivedData !=nil)
    {
        return YES;
    }
    else
    {
        NSLog(@"Data is null");
        return NO;
    }
}

上面的方法对我来说非常有用,所以每当我试图向服务器发送一些数据时,我总是使用这个低超时URLRequest检查我的内部网资源的可达性。

首先:在framework中添加CFNetwork.framework

代码:ViewController.m

#import "Reachability.h"

- (void)viewWillAppear:(BOOL)animated
{
    Reachability *r = [Reachability reachabilityWithHostName:@"www.google.com"];
    NetworkStatus internetStatus = [r currentReachabilityStatus];

    if ((internetStatus != ReachableViaWiFi) && (internetStatus != ReachableViaWWAN))
    {
        /// Create an alert if connection doesn't work
        UIAlertView *myAlert = [[UIAlertView alloc]initWithTitle:@"No Internet Connection"   message:NSLocalizedString(@"InternetMessage", nil)delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil];
        [myAlert show];
        [myAlert release];
    }
    else
    {
         NSLog(@"INTERNET IS CONNECT");
    }
}

我发现使用SimplePingHelper库很简单。

示例代码:chrishulbert/SimplePingHelper (GitHub)

-(void)newtworkType {

 NSArray *subviews = [[[[UIApplication sharedApplication] valueForKey:@"statusBar"] valueForKey:@"foregroundView"]subviews];
NSNumber *dataNetworkItemView = nil;

for (id subview in subviews) {
    if([subview isKindOfClass:[NSClassFromString(@"UIStatusBarDataNetworkItemView") class]]) {
        dataNetworkItemView = subview;
        break;
    }
}


switch ([[dataNetworkItemView valueForKey:@"dataNetworkType"]integerValue]) {
    case 0:
        NSLog(@"No wifi or cellular");
        break;

    case 1:
        NSLog(@"2G");
        break;

    case 2:
        NSLog(@"3G");
        break;

    case 3:
        NSLog(@"4G");
        break;

    case 4:
        NSLog(@"LTE");
        break;

    case 5:
        NSLog(@"Wifi");
        break;


    default:
        break;
}
}

苹果提供了一个示例应用程序,它正是这样做的:

可达性